Underwater weed cutter

ABSTRACT

An underwater weed-cutting device comprising a longitudinally adjustable shaft for immersing in a body of water, a drive motor mounted at one end of the shaft and cutting blades mounted at the other end of the shaft. A submersible float is adjustably mounted on the shaft intermediate its ends and contains an independently driven chopper mechanism an a suction device adapted to suckup and finely chop the weeds cut off at the bottom of the body of water for disposal, the intermediate submersible float being provided to maintain balance of the cutting device, to adjustably raise or lower the cutting blades in relation to the various depths of the body of water, and to vary the height of the chopper mechanism relative to the height of the weeds.

States Patent [72} Inventor Joseph D. Beattie 3,415,068 12/1968 Casey,Jr. et a1. 37/56 X 22794 Almond, East Detroit. Mich. 18021 3,429,062 2/1969 Nelson 37/72 X gr p: zfgfi i FOREIGN PATENTS 1 e e [45] Patented g 3 19.711 794,724 9/1968 Canada 37/N.D.

Primary Examiner Louis G. Mancene Assistant Examiner-J. A. Oliff 1 UNDERWATER WEED CUTTER Arromey-Hauke, Gifford and Patalidis 32 Claims, 11 Drawing Figs.

[52] 11.1.8.0 56/9 Aold 45/09 ABSTRACT: An underwater weed-cutting device comprising [50] Field of Search 56/8,9; a longitudinally adjustable haft f immersing in a body f water, a drive motor mounted at one end of the shaft and cutting blades mounted at the other end of the shaft. A sub- [56] References cued mersible float is adjustably mounted on the shaft intermediate UNITED STATES PATENTS its ends and contains an independently driven chopper 813,935 2/1906 Avery,J 37/56 mechanism an a suction device adapted to suckup and finely 1,220,197 3/1917 ConIes 37/54 chop the weeds cutoff at the bottom of the body of water for 1,275,851 8/1918 Comfort, 56/255 disposal, the intermediate submersible float being provided to 1,327,651 1/1920 Beaven 37/58 maintain balance of the cutting device, to adjustably raise or 1,531,477 3/1925 Dawson et a1. 37/65 lower the cutting blades in relation to the various depths of the 1,611,778 12/1926 Rathke 56/8 body of water, and to vary the height of the chopper 2,629,218 2/1953 Smith 56/9 mechanism relative to the height of the weeds.

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SHEET 0F INVENTOR JOSEPH D. BEATTIE ATTORNEYS Nu kokkwwhwm c UNDERWATER WEED CUTTER BACKGROUND OF THE INVENTION 1. FIELD OF THE INVENTION The present invention relates to apparatus for cutting and harvesting, or disposing of, marine vegetation. Such apparatus are known and are comprised in general ofa set of reciprocating or rotatable cutting blades adapted to be lowered into a body of water close to the bottom thereof to cut off the vegetation. Such underwater vegetation is a common problem in inland lakes or along river banks and may become quite hazardous to small boat operations and to swimmers and waders alike, since the vegetation, if not properly taken care of, becomes thick and entangled providing a ready trap for outboard propellers or for persons swimming or wading in the water. The uncontrolled underwater growth of plant life, as well as consequent accumulation of decaying vegetation, also contributes to an increased contamination of the body of water.

It is also known to cut and harvest underwater plant life for scientific purpose or for consumption. In many of these in stances, it is not only desired to cut off the marine vegetation, but also to collect the cut off plants for further use or for disposal.

II. BRIEF DESCRIPTION OF THE PRIOR ART Known underwater weed cutting and harvesting apparatus usually provide power driven cutting means suspended within the water from a platform, such as a boat or barge, and plant collection means such as a suction pipe or the like and a collector in the form of a strainer. The cutting means in these devices are usually installed at the intake end of the suction pipe and function by sucking a quantity of the plant life into the suction pipe where the plants are cut off automatically by the cutting means. The cutoff plant life is then sucked through the suction pipe into a strainer for drainage of the water sucked through the pipe together with the vegetation. These known apparatusexamples of which are disclosed, for instance, in U.S. Pat, No. l,57l,395, No. 2,320,283, No. 2,629,218 and No. 2,907,l62-are relatively slow in opera tion and usually of expensive construction. Furthermore, since the whole plants in the entire length as they are cut from the bottom of the water are being collected through the suction pipe and into the strainer it happens frequently that they get stuck in the pipe, especially where the pipe is bent, and this requires shutting off of the apparatus to free the stuck plants from the pipe. In addition, the plant collector, such as a net or a strainer, will be quickly filled because of the large size plants and weeds and therefore needs to be emptied frequently, causing further frequent interruption in the operation of the device.

A more serious drawback in these known devices employing plandconveyors in the form of large suction pipes is the large amount of water drawn into the pipe together with the cutoff SUMMARY OF THE INVENTION The present invention provides an improved underwater harvesting apparatus for more economical and less time consuming marine harvesting operations comprising novel means enabling the apparatus to be quickly moved about the body of water, providing high-speed cutting means and plant collecting means. I

This is accomplished by the provision of a fioatably suspended cutting apparatus provided with an intermediate float which provides a combined suction and fine chopping means to suck in the cutoff lengths of plants to be finely chopped by knife means within the float which are driven by the same means or independently of the cutting means. The finely chopped plant life is then sucked from the float member into a collection strainer or the like through a suction pipe which only needs to be of relatively small dimension due to the finely chopped condition of the vegetation. Likewise, due to the finely chopped condition of the plants, the strainer is able to collect and contain a much larger amount of vegetation than is ordinarily the case when the plants are collected as a whole.

By the improved means disclosed in the present invention, the main cutting blades are solely supported by a submerged float which maintains the blades at the desired depth close to the bottom of the body of water regardless of wave action to which the boat or barge may be subjected. The float itself is also independently adjustable relative to the main cutting blades so as to maintain the float closely adjacent the top of the vegetation in order to immediately suck in the cutoff plants to prevent them from floating away, although the whole apparatus is steadily in motion across the body of water.

The novel means disclosed herein further include independent drive means for the main cutting blades and the fine chopper within the float and in one embodiment provides means for counterrotating a pair of cutting blades. The fine chopper is preferably designed to operate at a higher speed than the main cutting blades, yet the submerged float maintains the apparatus in a perfect balance during operation.

Additionally, the present invention discloses novel multiple cutting means comprising opposite rotatable arms, each of which is provided with a multiple of disc cutters which are independently driven at a higher speed than the speed at which the arms are rotated.

Numerous other novel features and distinct advantages will become evident as the following detailed description proceeds with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS The several sheets of drawing illustrate various preferred forms of the invention and detail views of certain novel features embodied therein.

FIG. 1 illustrates a typical installation of one preferred form of the invention showing the apparatus in operation;

FIG. 2 is an enlarged detailed view of the present novel cutting mechanism shown in FIG. I and having parts broken away and shown in cross section for clarity;

FIG. 3 is a cross section through the motor shaft and cutter blade drive shaft arrangement taken substantially along line 3-3 of FIG. 2;

FIG. 4 is an enlarged cross section through the counterrotating cutter blade assembly of the cutting mechanism taken substantially along the line lli of FIG. 2.;

FIG. 4a is a view similar to FIG. 4 illustrating an alternate reversing gear arrangement for the cutting mechanism of FIGS. l and 2;

FIG. 5 is an enlarged cross section through the balancing float arrangement using a suction pump with integral chopper mechanism instead of the electric motor driven chopper assembly disclosed in FIGS. 1 and 2;

FIG. 5a is an enlarged fragmentary view of the pump and chopper portion of FIG. 5;

FIG. 6 is a transverse cross section through the aircoupling lock mechanism used in the float embodiment taken substantially along the line 66 of FIG. 5;

FIG. 7 shows in plan view an alternate cutting-blade mechanism which may be sued with either float embodiment in FIGS. 2 or 5',

FIG. I]. is an enlarged fragmentary longitudinal section through the cutting blade mechanism ofFIG. 7; and

FIG. 9 is a vertical section through the gear drive mechanism of the cutting blade arrangement in FIG. 7.

DESCRIPTION OF THE PREFERRED EMBODIMENT In reference to FIG. 1, which shows a preferred actual operational installation, the present novel underwater weed cutting and harvesting device broadly consists of a floating platform, barge or the like, forming a water conveyance of any desired configuration, adapted to be towed or moved by its own power along the surface of a body of water 22 which has a bottom 24. The body of water 22 may be a lake, river or the like which usually is not of excessive depth. The bottom 24 of the body of water sprouts marine vegetation 26 of various kinds such as seaweed or the like, which is desired to be removed for disposal or further processing for consumption or for chemical uses.

The floating platform 20 preferably supports a collector 28 in the form of a net or a strainer adapted to collect the cutoff vegetation 26. The strainer 28 may be supported on the platform 20 in any convenient fashion, and, as shown in FIG. I, is being supported over the side of the platform to which it is connected by a hinge 30 and held in suspended position by a cable 32 which is tackled to a mast 34 on the platform and around a winch 36 so that when the winch is operated the strainer 28 will be raised around its hinge 30 to empty it onto the platform 20 or into any suitable container provided for this purpose,

Carried by the platform 20 within an appropriate aperture 38 for vertical up and down adjustment therein relative to the platform 20 is an elongated tube 40 which is adapted for immersion into the body of water. and which is preferably of square cross section as seen in FIGS. 2, 3 and 6. The tube 40 is preferably assembled of a plurality of tubular sections 40a, b, c, etc, as shown in FIGS. 2 and 4. As more clearly shown in FIG. 4, the ends of the individual tubular sections have mating internal flanges 42 and opposite external flanges 44 so that any number of tubular sections may be assembled together to obtain the required length of the tube by fitting the internal flange 42 of one tube section into the external flange 44 of the next adjacent tube section, The assembly is then secured together by means of roll pins 46 or the like extending at opposite sides through both flange portions 42 and 44, Thus, the elongated tube 40 can be made of any desired length relative to the depth of the body of water.

The tube 40 carries within and for rotation therein, a drive shaft 48 of a length substantially corresponding to the length ofthe support tube 40 and, as seen in FIG. 4, is also preferably made of a plurality of individual sections 48a. b, 0, etc, corresponding to the lengths of the tubular sections 40a, b, etc. The drive shafts sections 48, 48a, 4811, etc. are connected to each other by universal joints 50, or if preferred they may be connected by splines, screw threads or the like. Thus, any number of shaft sections and corresponding tube sections may be added or removed from the tube and shaft assembly, as the case may be, and as required by the general depth of the body of water. i

The drive shaft 48 carries at its lower end, which will be suspended in the water, a counterrotating cutter blade assembly 52 comprising a pair of cutting blades 54 and 56, which are adapted to be rotated by a motor, engine or any other suitable prime mover 58, supported on the upper end of the tube 40 above the platform 20. Thus, with the tube and shaft assembly suspended within the water and upon operation of the prime mover 58, the cutting blades S456 will be rotated to cut off the vegetation 26 shortly above the bottom 24, as illustrated in FIG. 1, while the platform 20 is moved along the surface of the water.

In order to effectively collect the cutoff vegetation and to prevent the cutting blade assembly from excessive tumbling and whipping movement during the cutting operation due to the length of the tube and drive shaft assembly and to further reduce violent water currents caused by the counterrotating blades, a novel float means 60 is provided to floatingly support the tube 40 within the water. The tube 40 extends centrally through the float means 60 which is adjustably attached to the tube by means ofa clamp lock collar 62 having a hand screw 64 to release the clamp for vertical adjustment of the float means 60 up or down along the tube 40 and relative to the cutting blade 54--56. As seen in FIG. I, the float means 60 is suspended within the water and is adapted to floatingly retain the cutting blade assembly at a preselected depth regardless of the up and down movement of the platform 20 as caused by surface waves.

As shown in FIG. 2, and more particularly in FIG. 4, in order to prevent the tube assembly 40 from abruptly sliding down towards the bottom of the body of water upon release of the float lock collar 62 due to the weight of the cutter blade assembly 52 at the end of the tube, preferably an air bag or air chamber 53, or the like, is provided at the end of tube 40 which is of such proportions as to contain a sufficient amount of air to slow the descent of the cutter blade assembly when the lock collar 62 is released, to thus prevent any sudden downward drop of the cutter blade assembly. The air bag or air chamber 53 may be secured to the end of the tube 40 by any convenient means or may be made an integral part of the cutter blade assembly,

The float means 60 is a buoyant body adapted to be positioned below the surface of the water at any desired depth by means to be described hereafter, and accordingly, when clamped to the tube 40 is able to position the cutting blade assembly in relation to the bottom surface 24 of the body of water. The float means 60, as indicated in FIG. 2, carries a chopping blade assembly 66 which is preferably driven by a water sealed electric motor 68 concealed within the float means 60 so as to be protected against entry of water. The electric motor 68 is connected for operation by a watertight cable 70 to a source of electrical power, such as a power driven generator 72 or the like, positioned on the platform 20 as seen in FIG. 1 and provided with suitable motor controls (not shown) to drive the chopper mechanism 66 at a relatively high speed. Additionally, the float means 60 is provided with a suction chamber 74. around the electric motor in communication with the chopper mechanism 66 and connected by a pipe 76 to a suction pump 78 on the platform 20. Upon operation of the pump 78, the suction created around the chopper mechanism 66 draws the cutoff vegetation into the chopper mechanism where it is chopped up finely and then is drawn through the suction chamber 74 in the float means and through the suction pipe 76 into the pump 78 together with a nominal amount of water. The chopped up vegetation, together with the nominal amount of water, as drawn through the suction pipe 76, is expelled from the pump 78 through an ejection pipe 80 into the strainer 28 from which the water drains back into the body of water 22, Due to the finely chopped condition of the vegetation, only a small size suction pump and small size suction pipe need to be provided, which consequently also reduces the amount of water being sucked As will be described more in detail hereafter, the float means 60 contains an air chamber 82 of varying volume which is suitably connected by air hoses 84 and 86 to a compressor 88 or the like positioned on the platform 20, Suitable controls (not shown) are provided to selectively exhaust or introduce air into the air chamber 82 of the float through the hoses 84 or 86 respectively to thus raise or lower the float to adjust the depth of the cutting blade assembly 52 in relation to the varying contour of the water bottom 24, as "well as to adjust the spacing between the cutting blade assembly 52 and the chopper mechanism 66 to correspond generally to the height of the vegetation 26.

For safety reasons and to prevent the float from counterrotating during operation, the float means 60 is preferably attached by means of a cable 87 of adjustable length to the platform 20 for safeguarding and for towing the float along when the platform is moving across the body of water and to prevent the loss of the float and cutting mechanism if it should become dislodged from the platform for whatever reason. Since the float means is nonrotatably supported by its engagement with the square tube 40 and by means of the additional tethering attachment by the cable 87 to the platform 20, the float means is effectively prevented from counterrotation during the operation of the device.

As can be seen from FIGS. 1 and 2, the diameter of the float means 60 is substantially equal to the rotational diameter of the cutting blades 54-56 and is preferably supported in a vertical distance from the cutting blades which is such that only a minimum amount of water swirl will be produced between the float and the cutting blades, which is further neutralized by the suction action of the suction chamber 74 in association with the fine chopping mechanism 66 so that the cutoff lengths of plant life from the bottom of the water will be easily sucked into the chopping mechanism of the float and will be effectively prevented from floating away between the float and the cutting blades. Due to the substantially similar diameters of the float and cutting blades, the float in effect provides an effective shield within which the cutoff vegetation is forced to float straight upwardly regardless of the linear movement of the cutting device across the body of water. The protective ness of the shield, in order to cause an upward flow, is further enhanced by the provision of a cutter blade guard 90 in the form of a flared shield extending circumferentially around the bottom of the float means 60 to which it may be suitably attached by welding or the like.

Thus, in an operational installation of the present novel device, the float means 60, as will be described, maintains an equilibrium of weight in order to keep the cutting blade assembly 52 at a specific depth relative to the surface contour of the bottom 24 of the body of water.

With specific reference to FIGS. 2 and 3, the float means 60 comprises a flat-shaped tank 92 which is made up of an upper shell 94 and a corresponding lower shell 96 which each have a radial flange 98 and 100 respectively, by which the two shells are clamped together by means of a plurality of fasteners 102 much in the form ofa diaphragm chamber.

Centrally the lower shell 96 is provided with an aperture defined by a circumferential internal wall portion 104 within which is supported a rotatable chopper blade assembly 66 of any conventional construction. The bottom wall of the lower shell 96 around the chopper blade assembly 66 is provided with a plurality of apertures 106 which allows water to enter the tank 92. The upper shell 94 has a corresponding central aperture defined by a circumferential internal wall 108 and comprising a suction chamber 107 in communication with the chopper blade assembly 66 and suction chamber 74. The air chamber 82 of the tank 92 is adapted to be selectively supplied with air or exhausted by means of the air inlet hose 84 and the exhaust hose 86 which, as previously described, are connected to the suitably valved compressor 88 or the like positioned on the platform 20. Centrally attached to the upper shell 94 by welding or other suitable means is a cylindrical housing 116 extending upwardly therefrom and which contains the sealed electric motor 68 previously mentioned which is adapted to drive the chopper blade assembly 66. The cylindrical housing 116 forms the suction chamber 74 around the electric motor which is in communication with the suction chamber 107 formed by the internal wall 108 in the upper shell 94.

As mentioned herebefore, the float means 60 is adapted for vertical adjustment along the square tube 40 to obtain the most effective spacing of the float means relative to the cutting blade assembly 52, which will depend on the depth of the body of water and the height of the vegetation. To this effect the square tube 40 extends centrally through the float means 60 which is normally secured to the tube in the required position by means of the clamping collar 62 previously mentioned which is a part of or is attached to the cylindrical housing 116 and provided with the hand screw 64 or the like 64 adapted to clamp the float means securely to the tube 40.

As illustrated in FIG. 3, the rotor of the electric motor 68 carries a sleeve 118 adapted for sliding movement along the tube 40 which has a cylindrical bearing surface 120 for rotational support of the tubular drive shaft 122 of the electric motor 68 adapted to drive the rotor knives 67 of the chopper assembly 66 upon operation of the electric motor 68.

With reference now to FIG. 4, the lower end of the square tube 40 is attached to a plate 124 by means of a central hub portion 126 of the plate into which the end of the square tube extends. The end of the cutter blade drive shaft 48 extends beyond the end of the square tube and is drivingly connected adjacent the under side of the plate 124 by means of a key 130 or the like to a rotor 128 which carries a cutting blade 54 for rotation therewith. Preferably, a wear plate 132 is positioned between the rotor 128 and the support plate 124 for ease of rotation. The drive shaft 48 extends further downwardly and provides at its end a pilot portion 134 of reduced diameter adapted for rotational support within an aperture 136 in the bottom ofa housing 138 of the cutting blade assembly 52. The aperture 136 is preferably closed in the assembly by a watertight plug, such as a Welch plug 140 to prevent the entrance of water therein. The pilot portion 134 provides a shoulder 142 by which the drive shaft 48 is rotationally supported on a thrust bearing 144 positioned between the shoulder and the housing 138. Adjacent the pilot portion 134, the drive shaft 48 carries a bevel gear pinion 146 drivingly connected thereto by a key 148, splines or the like. The bevel gear pinion 146 is in constant mesh with an idler gear 150 positioned transverse thereto which is supported for rotation within the housing 138 by means of a stub shaft 152 having a pilot portion 154 for rotation within a bearing 156 disposed in an aperture 158 in the housing 138. The outer end of the aperture 158 is likewise closed by a watertight Welch plug 160 to prevent the entrance of water therethrough. The idler gear 150 is in constant mesh with a driven bevel gear 162 positioned oppositely to the pinion 146 around the drive shaft 48 which freely rotatably extends therethrough. The driven bevel gear 162 is attached by fasteners 164 or the like to another rotor 166 which carries or is integral with the other cutting blade 56 to be rotated thereby. Preferably, a wear ring 168 is positioned between the upper end of the housing 138 and the underside of the second rotor 166. Likewise, a wear plate 170 is positioned between the first rotor 128 and the second rotor 166 to facilitate rotation of the rotors in opposite directions. The second rotor 166 and its drive gear 162 are supported for rotation around the shaft 48 on a bushing 172 press fitted within both members and having a loose fit around the shaft 48 for rotation relative thereto.

Preferably the housing 138 is filled prior to assembly with a lubricant for lubrication of the gear mechanism during operation or, alternatively, the gears 146, 150 and 162 could be made of tough, corrosion resistant synthetic material which needs no lubrication.

Thus, in operation, when the drive shaft 48 is being rotated by the prime mover 58 on the platform 20 it rotates directly the first rotor 128 and the cutting blade 54 in the direction of rotation of the drive shaft. The drive shaft 48 rotates the pinion gear 146 which rotates the idler gear 150. The idler gear in turn rotates the second rotor 166 by means of its bevel gear 162 in a direction opposite to the first rotor 128 thus rotating the cutting blade 56 in a direction opposite from the cutting blade 54.

An alternate embodiment is illustrated in FIG. 4a which accomplishes the positioning of the counterrotating cutting blades below the gear reversal mechanism to permit cutting of the underwater vegetation closer to the bottom.

In this instance, the drive shaft 48 extends through a housing 138a to exit at the lower end of the housing which is nonrotatably attached to the end of the support tube 40 by means of a central hub portion 126a and fasteners 127. The end of the drive shaft 486 extending out of the housing 1380 is splined or serrated as at 49 to receive the rotor 166a of the lower cutting blade 56 for rotation thereby. Within the housing 1380 at the upper end thereof a driving gear 146a is attached to the drive shaft 480 by means of a key 148a or the like to be rotatable therewith. The: driving gear 14611 is in constant mesh with an idler gear 150a rotatively supported within the housing 1380. The idler gear 1500 in turn is in constant mesh with a driven gear 162a in the lower end of the housing 138a and which is supported on a bushing 172a around the drive shaft 48 for rotation relative thereto. The hub portion 163 of the driven gear 162a extends out of the lower end of the housing 1380 through a housing aperture 139 and is splined or serrated as at 165 to receive the rotor 128a of the upper cutting blade 54 for rotation therewith. The rotors 128a and 166a of the cutting blades 54 and 56 respectively are suitably spaced apart by means of a wear ring 167 placed around the shaft 48 between the rotors 128a and 1660. The aperture 139 in the lower end of the housing 138a is sealed against the upper rotor 1280 by means of a seal 169 to prevent the entrance of water into the housing.

Thus, in operation, upon rotation of the drive shaft 48 the lower blade 56 will be directly rotated by the drive shaft in the same direction as will the driving gear 146a. Rotation of the driving gear 146a rotates the idler gear 150a which in turn rotates the driven gear 1620 in a direction opposite to the driving gear [460. Due to the attachment of the driven gear 162a to the upper blade 54 this blade will be rotated in a direction opposite from the direction of the lower blade 56, Due to the position of the blades below the gear housing 138a the blades can be positioned as close to the bottom 24 of the body of water as may be desirable.

The floating platform is towed or moved under its own power slowly across the body of water 22 having its float means 60 and cutting blade assembly 52 suspended within the water as shown in FIGS. 1 and 2. The cutting blade assembly 52 is positioned close to the bottom 24 of the body of water and is maintained in this position by the float means 60 which is clamped to the tube 40 in such spaced position relative to the cutting blade assembly 52 as to provide maximum suction effect without drawing excessive amounts of water. As a bed of underwater vegetation is being approached, the prime mover 58, electric motor 68 and suction pump 78 are started causing counterrotation of the cutting blades 54 and S6 at a speed governed by the prime mover 58 thereby cutting off the underwater vegetation 26 close to the bottom 24. The counterrotation of the adjacent superimposed blades 54 and 56 assures a balanced operation of the device during cutting and prevents violent swinging or whipping motions of the cutter assembly. The cutoff lengths of seaweed 26 or other underwater vegetation is caused to flow vertically upwardly towards the float means 60 positioned directly above the cutting blade assembly 52. The suction pump 78 on the platform 20 causes the vegetation .to be sucked into the chopper blade assembly 66 of the float means in which the rotor knives 67 are being continuously rotated at a relatively high speed by the electric motor 68 which receives power from the generator 72. The rotor knives 67 of the chopper assembly are preferably rotated at a much higher speed than the cutting blade assembly 52 for fast chopping action to finely chop the lengths of vegetation as they are sucked into the chopper assembly 66. The chopped vegetation is then sucked by the pump 78 through the suction chambers 107 and 74 and suction pipe 76 to be expelled through the ejection pipe 80 into the strainer basket 28 together with a nominal amount of water simultaneously sucked in which is caused to drain from the strainer 28 back into the body of water. As the apparatus moves through the water, the contour of the bottom 24 may change constantly and, in accordance with the changing contour, the float means 60 and cutter blade assembly 52 may be repositioned as a unit relative to the bottom surface of the water to substantially maintain a constant height ofthe cutting blade assembly above the bottom 24 and, conversely, prevent the cutting blade assembly from hitting bottom and thus damaging the cutting blades. This repositioning during the cutting operation is accomplished by the provision of the air chamber 82 and the float means 60 which is of varying volume. By introducing air into the chamber through the air hose 84, water will be forced out of the chamber th gh th apertures 106. The provision of increased air and less water within the tank 92 of the float means causes an upward buoyancy of the float means thus raising the cutter blade assembly 52 since the float means is clamped to the support of the support tube 40. Conversely, if air is expelled from the air chamber 82, more water will be permitted to enter through the apertures 106 thus adding weight to the float means, causing it to sink deeper into the body of water and thereby lowering the cutter blade assembly in relation to the contour of the bottom 24 of the water.

With reference now to FlGS., 5a, 5 and 6, there is illustrated an alternate embodiment of the float means, together with an alternate suction and chopping blade arrangement associated therewith. In this embodiment, a float means 60a, receives and supports an electrically driven suction pump assembly 174 having a housing 175 and which may be generally of the type known as a trash pump or submersible drainage pump, which are designed to operate submerged in water. An example of such a pump may be the Model B2050 manufactured by the Flygt Corporation, Stamford Connecticut The suction pump assembly 174 is slidingly supported on the square tube 40 by means of a bushing 176 which has a cylindrical outer bearing surface 178 for the rotation of a hollow drive shaft in the form of a sleeve member 180 therearound. The hollow drive shaft 180 is secured for rotation to a rotor 182 of an electric motor 184 within the housing 175 of the pump assembly 174 and which has electrical connection through wires 186 and cable 70 with the generator 72 on the platform 20 (FIG, 1). The hollow drive shaft 180 extends downwardly through the pump housing 175 and through an inlet 188, and carries an impeller blade assembly 190 inwardly of and immediately adjacent to the inlet 188 for rotation by the hollow drive shaft 180. Below the inlet 188, a bevel pinion gear 192 is secured to the hollow drive shaft 180 by means ofa key 194 or the like to be rotatable with the drive shaft 180 and is held axially in position on the shaft by a snap ring 196 or the like. The pinion gear 192 is in constant mesh with an idler bevel gear 198 provided with a stub shaft 200 which is supported for rotation within a bushing or hearing 202 in an aperture 204 provided within an internal boss portion 206 which extends from the inner surface of an extension housing 208 integral with or secured to the pump housing 175 to enclose the inlet 188. The end of the idler stub shaft 200 is provided with a pilot portion 210 of reduced diameter which extends into a smaller aperture 212 coaxially aligned with aperture 204 to thus retain axial alignment of the idler gear 198. The thrust load of the idler gear 198 is absorbed by means of a thrust bearing 211 around the pilot portion 210. The outer end of the aperture 212 is suitably sealed by means of a Welch plug 214 or the like to prevent the entrance of water therethrough and the bearing aperture 204 is likewise suitably sealed by sealing means 216 to prevent the entrance of water and chopped vegetation into the bearing. The idler gear 198 is in constant mesh with a driven bevel gear 218 positioned oppositely from pinion gear 192 for rotation around the hollow drive shaft 180 in a direction opposite to the direction of rotation of the pinion gear 192. The driven gear 218 has a hub portion 220 which extends into the hub portion 222 of a chopper blade assembly 224 to which it is drivingly connected by means of screws 226 so that upon rotation of the driven gear 218 the chopper blade assembly will be rotated. Needle bearings 228 or the like are positioned between the hollow drive shaft'l80' and the driven gear 218 to facilitate rotation of both members relative to each other. The needle bearings 228 are retained in place by opposite retaining rings 230 and are suitably sealed by sealing means 232. The lower end of the extension housing 208 is closed by a perforated plate 234 centrally through which the bushing 176 extends, having a radial flange 177 centrally supporting the plate 234. Located on top of the plate 234, opposite the flange 177, is a wear ring 236 upon which the ends of the hollow drive shaft 180 and the hub 220 of the driven gear are supported. The chopper blade assembly 224 is provided with a plurality of chopping blades 225 which are adapted to cooperate with perforations 235 provided in thestationary plate 234 to chop up the marine vegetation 26 as it is sucked through the plate by the suction created by the rotating impeller 190.

The reversing gears, as well as the bearings and bushings associated therewith, can preferably be made of corrosion resistant hard plastic material, such as Nylon or Teflon which do not need lubrication and can be of a rugged construction to withstand their contact with the chopped vegetation and other foreign matter which may be floating in the water, although, due to the constant suction through the chopper and gear mechanism, there is substantially no danger of any solid material becoming permanently lodged in the mechanism.

In operation of this embodiment, the electric motor I84 of the submerged pump 174 is started by the generator 72 to rotate the hollow drive shaft 188 which rotates the impeller 190 to create a suction in the pump housing I75 to suck in the vegetation 26 cutoff by the cutting blade assembly 52. As the impeller 196 is rotated, the drive pinion 192 is likewise rotated by the drive shaft 1188 in the same direction and rotates the idler gear ll98 in the extension housing 208. The idler gear in turn rotates the driven gear 2l8 but in a direction opposite from the direction of the driven gear I92. Gear 218 causes rotation of the chopper blade assembly 224 so that the impeller and chopper blade assembly are rotated in opposite directions to create a force balance in the pump assembly to prevent the float means 60a from swinging or turning around, which might occur if both the impeller and the chopper blade assembly are rotated in the same direction. The suction created by the rotating impeller forces water together with the cutoff seaweed to be sucked through the perforations 235 in the stationary bottom plate 234 to enter the extension housing 208 in which they are chopped. into small pieces by the highspeed chopping blades 225. The chopped up seaweed together with a nominal amount of water is then sucked through the pump inlet 188 into the suction channels I73 provided within the pump housing 175. The suction channels 173 are in communication with a suction pipe 76a which is in direct communication with the ejection pipe 80 (FIG. 1) to eject the chopped seaweed and the water into the strainer basket 28. Thus, this embodiment eliminates the provision of the separate suction pump 78 on the platform 20.

In both embodiments of FIGS. 2 or 5, the chopper mechanisms as well as the cutter blade assembly may be conjointly rotated by the electric motor 68 or 184 in the float means 60 or 60a so as to eliminate the provision of a separate driving means such as the prime mover 58 for the cutting blade assembly 52.

The depth positioning of the float means and cutting assembly is accomplished by alternate means as illustrated in FIGS. 5 and 6. In this embodiment, the float means 60a is clamped to the square support tube 40 in selective position relative to the cutting blade assembly 52 by means of an air clutch mechanism 238 which is part of the pump housing 175 contained in an extension 240 at the upper end thereof and through which the tube 40 extends. Asseen in FIG. 6, the air clutch 238 comprises an inflatable annular air chamber 242 around the support tube 40 formed by an inner annular diaphragm 244 and an outer annular diaphragm 246. The inner annular diaphragm has a plurality of friction members 248 adapted to frictionally grip the surfaces of the square support tube 40 upon inflation of the air chamber 242 and the outer annular diaphragm 246 is provided with an external annular friction surface 250 adapted to be frictionally urged against the internal surface 252 of the air clutch housing 240 upon inflation of the air chamber 242. The air chamber 242 is connected by a fitting 254 any} a conduit 256 to a source of compressed air 258 (FIG. 5) which may comprise a tank connected to a compressor 260 and provided with a relief valve 262, all of which are positioned on the platform 20. The source of compressed air 258 is also connected by means of a conduit 264 to the air chamber 82 of the tank 92 of the float means 60a to selectively provide the air chamber with compressed air.

iii

The conduits 256 and 264 are selectively connected to the source of compressed air by means of a control valve 268 which is likewise positioned for manipulation by the operator of the apparatus on the platform 28. The outlet conduit 265 of the air tank is connected to the control valve 268 through a one-way valve 266 and, normally, for cutting operation of the apparatus the valve 268 will be in a position as shown in FIG. 5, that is, the source of compressed air will be directly connected to the air chamber 242 of the air clutch 238 through communicating valve bores 270 and 272 in the rotatable valve member 269 of the control valve 268 establishing direct communication between the conduits 26.5 and 256 and thereby inflating the air chamber 242 to expand the diaphragms 244, 246 in order to establish frictional contact between the friction members 248 and the support tube 40 and friction member 250 and the clutch housing 240 to thus lock the float means 60a solidly onto the support tube 40. In order to adjust the distance of the cutting-blade assembly 52 supported at the lower end of tube 40, in relation to the float assembly 60a, the air clutch 238 must be released, which is accomplished by the operator rotating the valve member 269 of the control valve 268 in a clockwise direction, as shown in FIG. 5, thereby closing off the valve bores 270 and 272 and bringing the conduit 256 into communication with an exhaust valve bore 274 which opens to the atmosphere, thereby bleeding the clutch air chamber 242 to the atmosphere and releasing the friction members 248 and 250. Thereupon, the cutting-blade assembly on the support tube 40 can be manually raised or lowered by sliding the tube through the center of the float means which itself stays in place at the selected depth determined by the water to air ratio in the tank 92. When a desired depth of the cutting-blade assembly relative to the bottom 24 and to the float means is attained, the support tube 40 can again be locked to the float means 60a by counterrotation of the valve member 269 of the control valve 268 to bring the valve bores 270, 272 again in alignment with conduits 256 and 265.

In order to vary the depth of the cutting blade assembly 52 relative to the changing bottom surface of the water during operation of the apparatus, the operator will rotate the valve member 269 of the control valve 268 in a counterclockwise direction from the position shown in FIG. 5 to align the valve passage 276 with the conduit 265 and the conduit 264, thereby connecting the source of compressed air 258 with the air chamber 82 in the tank 92 to introduce air into the chamber and thereby expelling water from the chamber through the apertures 186. This increases the buoyancy of the float means 60a to cause it to rise and thus raise the cutting blade assembly 52 due to the attachment of the float means to the support tube 40. The rotation of the valve member 269 causes disruption of communication between the source of compressed air and the air clutch 238 through valve bores 270 and 272. However, the air clutch remains locked due to the entrapment of compressed air therein. When it is desired to lower the cutting-blade assembly by the float means 60a, the valve member 269 of the control valve 268 is rotated further in a counterclockwise direction as illustrated in FIG. 5 to close off the conduit 265 from the source of compressed air and to align the conduit 264 with an exhaust valve bore 278 in the valve member 269 which is open to the atmosphere and thus bleeds air from the air chamber 82 to permit an increase of water entrance through the apertures 106 into the chamber, thereby decreasing the buoyancy of the float means 60a causing the cutting-blade assembly to be lowered. In either of the latter two positions of the valve member 269, the air clutch 238 remains in the locked or engaged position clue to the amount of air under pressure trapped; therein upon disruption of communication with the source of compressed air.

FIGS. 7 79 illustrate an alternate, mechanically driven, multiple cutting-blade assembly 280 which can be substituted for the dual cutting-blade assembly 52 in FIGS. ll, 2 and 4 and which may be used with either float means 66 in FIG. 2 or float means 60a in FIG. 5.

The cutting-blade assembly 280 comprises a cylindrical, cup-shaped cutter drive mechanism housing 282 whose upper end is closed by a cover 284 (FIG. 9) attached to the housing as by bolts 286 or the like. The housing 282 is rotatable, as will be described, relative to the square support tube 40 which extends downwardly upon it but which ends adjacent the upper surface of the cover 284 whereas the drive shaft 48 extends into the housing 282 through an aperture 288 provided in the cover 284. A bushing or bearing 290 is located in the aperture 288 around the drive shaft 48 and is preferably press fitted into the aperture to facilitate rotation of the housing and the drive shaft relative to each other, and an appropriate seal 292 is provided between the end of the tube 40 and the cover 284 to seal the aperture 288 against the entrance of water into the housing. The drive mechanism housing 282 is rotatably supported relative to the tube 40 by any means such as cables 294 attached to brackets 296 secured to the cover 284 of the housing. The support cables 294 extend upwardly and are secured at the other end to a collar 298 which is rotatably retained within an annular channel 300 of a bushing 302 which is welded or otherwise secured to the support tube 40. The cables 294 are tightened to support the rotatable housing and to maintain a tight sealing fit at the seal 292.

As illustrated in FIG. 7, attached to opposite sides of the housing 282 are a pair of arms 304 and 306 respectively extending in opposite directions away from the housing and which are rotatable therewith in the direction of the arrow as shown. The arms 304 and 306 each retain and support a plurality of cutting discs 308 provided with cutting teeth 309 around their circumference which are rotatable in opposite directions as indicated by a driving gear mechanism hereinafter to be described. In general, with the cutting-blade assembly 282 installed in place of the cutting-blade assembly 52 the arms 304 and 306 will be continuously rotated against the underwater vegetation at a relatively slow speed with simultaneous rotation of the cutting discs 308 at a considerably faster speed to cut off the vegetation caught between the teeth of the rotating cutting discs.

With specific reference to FIGS. 8 and 9, the drive mechanism contained within the housing 282 is constructed as follows: the drive shaft 48, which is powered by the prime mover 58 on the platform 20 or either electric motor 68 or 184 in the float means 60 or 60a, extends vertically through the housing and is provided at its end with a pilot portion 310 of reduced diameter which is piloted for rotation within a bearing 312 positioned in an aperture 314 in the bottom 316 of the housing. The outer end of the aperture 314 is preferably closed by a sealing member such a Welch plug 318 to prevent the entrance of water. The shoulder 320 formed by the reduced diameter pilot portion 310 of the drive shaft is rotatively supported on a wear ring or thrust bearing 332 located on the inside of the bottom wall 316 of the housing. The lower end of the drive shaft supports a pinion bevel gear 324 attached thereto for rotation therewith and which is vertically supported for absorption of the thrust load on the thrust hearing 332, The pinion gear 324 is rotatable with the drive shaft 48 and is in constant mesh with an idler gear 328 positioned for rotation in the housing 282 and which is of larger diameter than the drive pinion and contains a greater number of teeth to obtain a reduction of rotational speed. The idler gear 328 in I the housing 282 is in constant mesh with a driven bevel gear 330 which is of identical size as the idler gear 328 and which is positioned opposite from the drive pinion 324 around the drive shaft 48. The driven gear 330 is attached as by fasteners 332 or the like to the underside of the cover 284 for rotation therewith and has a central aperture 334 adapted to receive the bushing 290 for rotation relative to the drive shaft 48. Thus, as the drive shaft 48 is rotated by the prime mover 58 (FIG. 1) or electricmotor 68 or 184 (FIG. 5), the drive pinion.

324 will be rotated to rotate the idler gear 328 which in turn rotatesthe driven pinion 330 by which the housing 282 together with its attached arms 304 and 306 will be rotated around the drive shaft in the direction opposite to the direction of the rotation of the drive shaft and at a slower speed than that of the drive shaft due to the speed reduction in the gearing 324,328 and 330.

The portion of the drive shaft 48 extending within the housing 282 is provided with a worm gear 334 securely attached thereto by any conventional means for rotation therewith and positioned between the drive pinion 324 and driven gear 330. The worm gear 334 is adapted to be in constant mesh with a driven gear 336 positioned centrally in the housing 282 on an axis at a right angle to the axis of the worm gear 334. The driven gear 336 is secured for rotation to a horizontal shaft 337 extending at a right angle to the drive shaft 48 in both directions from the gear 336 and through opposite sidewalls 338 and 340 respectively of the housing 282 and outwardly thereof into the arms 304 and 306 respectively. The driven shaft 337 is rotatably supported in the opposite sidewalls 338 and 340 in bushings or bearings 342 within apertures 344 which are suitably sealed outwardly by sealing means 346 to prevent the entrance of water into the housing 282. The 0pposite portions of the driven shaft 337 extending longitudinally along the arms 304 and 306 are provided at spaced intervals with worm gears 348 which are suitably secured thereto for rotation thereby and which are adapted to drivingly mesh with appropriate worm ring gears 350 which, as illustrated in FIG. 9, are secured on top of the cutting discs 308 to thus rotate the cutting discs upon rotation of the driven shaft 337. Each of the cutting discs is rotatably supported by means of a stem 352 piloted within a bushing 354 located in a lower support plate 356 of each arm 304 and 306 which are suitably fastened by welding or the like to the housing 282. Intermediate the drive worm gears 348, the driven shaft 337 is supported for rotation within bushings or bearings located in appropriate boss portions 360 integrally extending between the worm gears 348 from upper support plates 362 of each arm 304 and 306 which are likewise suitably secured to the housing 282, as for instance by means of screws 364.

As seen in FIGS. 7 and 8, the lower support plates 356 of the arms 304 and 306 are provided in the direction of their respective rotation with outwardly extending pointed blades 366 between adjacent cutting discs 308 which are adapted to catch and direct the under water vegetation between the cutting discs so that the stems of the vegetation will be sheared off between the blades and the toothed edges of the rotating cutting discs.

In operation, when the drive shaft 48 is rotated the cutter mechanism housing 282, together with the attached arms 304 and 306, is rotated by the speed reducing gearing 324, 328 and 330 as previously described in a direction opposite to the direction of rotation of the drive shaft and at a considerably slower speed. Simultaneously, the cutter drive shaft 337 is rotated by the worm gear mechanism 334, 336 at'the same speed as the drive shaft 48 to likewise rotate the cutter discs 308 at the same speed, that is considerably faster than the speed of rotation of the housing 282. As seen from FIGS. 7 and 8, the vertical rotational axis of the plurality of cutter discs 308 on the arm 304 are offset from the vertical rotational axis of the cutter discs supported on the other arm 306 which are positioned towards the opposite side of the respective worm drive gears 348 so that in fact, although the cutter drive shaft 337 rotates in one direction, the opposite cutter discs will be rotated in opposite directions as indicated by the respective arrows. This arrangement further enhances the stability and balance of the cutting device preventing any out of balance condition during the cutting operation which otherwise would add a sever strain to the cutting mechanism.

The cutting blade assembly 280 in FIGS. 7-9 as previously mentioned can be used with either the float means 60 in FIG. 2 or 600 in FIG. 5 for depth adjustment of the cutter assembly relative to the bottom of the water and adjustment relative to the float means in the same manner as hereinbefore described in connection with FIGS. l6.

Any desirable equal number of cutting discs may be employed at each arm 304 and 306, however, the use of three cutting discs at each arm as shown will be sufficient in most applications.

To further facilitate the depth adjustment of the cutter as semblies 52 or 280 relative to the bottom surface of the body of water and for proper spacing between the cutter assembly and the float means appropriate depth markings (not shown) may be provided on the support tube 40 in addition to a depth gauge (not shown) for the float means which will be responsive to the air to water ratio in the float tank 92 to indicate the depth position of the float means. Although such means are not particularly described herein, they are considered to be obvious additions hereto.

Obviously, if desired for economical or other purposes, the float means 60 or 600 could be attached solidly to the tubular support 40 completely eliminating the adjustment features of the lock collars 62 or 238, thus the device would be adjustable only in regard to the depth of the cutting blade assemblies. This arrangement may be preferable where the grown height of the underwater vegetation is known or can be determined.

Conversely, if the lock collars 62 or 238 are being used, they could be separate from the float means so as to be independently adjustable along the support tube 40 to retain the float means at the desired height above the cutting blade assemblies.

Likewise, instead of the floating platform 20, all the components supported thereon could be supported on a land conveyance moving along the water edge. This arrangement would be of particular advantage for underwater cutting along river banks or other shallow bodies of water.

The above alternates are considered to be obvious variations of the apparatus herein disclosed.

Thus the present invention provides an effective, high speed, semiautomatic seaweedcutting device of universal adaptability for a variety of water bodies wherever underwater vegetation is present. The provision of the fine chopping device in addition to the novel cutter blade mechanisms is of particular advantage in that it provides quick disposal of the cutoff vegetation together with a greater storage capacity of the fine chopped weeds. A further particular and important advantage is the depth adjustable float means disposed at an adjustably variable height above the cutter assembly to balance the rotating cutter mechanism and to provide an effective suction shield for the cutoff vegetation.

The present invention may be embodied in certain other forms without departing from the spirit and the essential characteristic thereof, therefore, the present embodiments are considered to be illustrative only and not restrictive, the scope ofthe invention being indicated by the appended claims rather than by the foregoing description.

I claim: 1. Apparatus for cutting underwater vegetation comprising: a conveyance movable on the surface ofa body of water, a vegetation collector carried by said conveyance, electrical power means and an air compressor carried by said conveyance, a longitudinal support member extending from said conveyance into said body of water and longitudinally movable relative thereto so as not to be affected by up and down movement of said conveyance, a cutting device rotatably attached to the lower end of said support member, and a submersible float means carried by said support member adapted to floatingly carry said support member and said cutting'device in a submerged position within said body of water, said float means comprising an air chamber connected with said air compressor,

said float means having an electric cutter driving means operably connected with said electrical power means, and

suction means associated with said float means to extract said vegetation cutoff by said cutting device for disposal into said collector.

2. The apparatus as defined in claim ll, further comprising control means associated with said compressor to control the amount of air within said air chamber of said float means.

3. The apparatus as defined in claim 2, in which said air chamber of said float means is perforated to allow the introduction of water thereinto and said control means is effective to vary the ratio of air to water in said air chamber for changing the depth of said float means within said body of water.

4. The apparatus as defined in claim 1, further comprising means to selectively lock said float means on said longitudinal support member at a preselected height above said cutting device, and said cutting device being provided with means to slow the descent of said cutting device upon release of said lock means.

5. The apparatus as defined in claim 4, in which said selec' tive locking means is an air clutch connected with said compressor.

6. The apparatus as defined in claim 1, in which said float means contains a chopping device having rotatable chopping blades coaxially disposed above said cutting device and means to drive said chopping device at a speed greater than the rotational speed of said cutting device.

7. The apparatus as defined in claim 6, in which said suction means is adapted to suck said vegetation cutoff by said cutting device into said chopping device for fine chopping of said vegetation.

8. The apparatus as defined in claim 6, in which said means to drive said chopping blades of said chopping device comprises an electric motor contained within said float means connected for operation to said electrical power means.

9. The apparatus as defined in claim 8, in which said suction means comprises a pump contained in said float means to be driven by said electric motor simultaneously with said chopping device.

10. The apparatus as defined in claim 9, in which said pump comprises an impeller driven by said electric motor and further comprising means to drive said impeller in a direction opposite from the rotational direction of said chopping blades of said chopping device.

ill. The apparatus as defined in claim 10, in which said drive means comprises a reversing gear mechanism embodied in said float means.

12. The apparatus as defined in claim 1, in which said suction means comprises a pump carried by said conveyance having a suction pipe connected to said float means and an ejection pipe connected to the outlet of said pump for disposal of said cut off vegetation into said collector.

13. The apparatus as defined in claim l, in which said cutting device comprises a pair of superimposed cutting blades and drive means to rotate said pair of cutting blades in opposite directions.

14. The apparatus as defined in claim 13, in which said drive means comprises a reversing gear mechanism drivingly connected to said pair of cutting blades.

15. The apparatus as defined in claim 1, in which said float means is connected to said conveyance by an extensible cable to counteract rotation of said float means around said longitudinal support member during operation ofsaid apparatus.

16. The apparatus as defined in claim 6, in which said float means if provided with an annular shield extending outwardly and dowgnwardly towards said cutting device to effectively in crease the suction of said suction means to guide said cut off vegetation into said chopping device.

17. An underwater weed cutting device comprising:

a drive shaft,

a cutting mechanism for cutting off vegetation and drivingly connected to said drive shaft for rotation thereby,

a submersible, buoyant, balancing and positioning device supported around said drive shaft,

chopping means carried by said balancing and positioning device,

suction means connected with said chopping means for sucking said vegetation cut off by said cutting mechanism into said chopping means,

power means to drive said cutting mechanism and said chopping means,

said balancing and positioning device provided with means for varying the buoyancy thereof to selectively vary the submerged depth of said cutting mechanism, and

means to selectively vary the distance between said balancing and positioning device and saidcutting mechanism along said drive shaft.

18. In the device as defined in claim 17, said suction means comprising a closed chamber disposed within said balancing and positioning device in communication with said chopping means, said chamber having an outlet in communication with a suction pipe, said suction pipe being in communication with the inlet of a pump positioned remote from said balancing and positioning device and ejection means connected to the outlet of said pump for disposal of said vegetation cut off by said mechanism.

19. In the device as defined in claim [7, adjustable locking means provided around said drive shaft to selectively retain said balancing and positioning device at a predetermined height around said drive shaft relative to said cutting mechanism, and means associated with said cutting mechanism to slow the descent of said cutting mechanism upon release of said locking means.

20. In combination with an underwater vegetation-cutting device attached to an elongated shaft, a buoyant float means supported on said shaft, said float means comprising:

a hollow body adapted to be selectively filled with air to increase or decrease its buoyance,

means to lock said float means onto said shaft at infinitely variable selected positions along at least a portion of the shaft to vary spacing from said cutting device, and

control means to selectively vary the volume of air within said hollow body to raise or to lower said cutting device when said float means is locked on said shaft.

21. The combination as defined in claim 20, in which said means to lock said float means onto said shaft comprises an air clutch having a housing disposed around said shaft, an annular air chamber within said housing defined by an annular diaphragm having spaced walls, friction members secured to the outside of said spaced walls for frictional locking contact against said housing and said shaft upon the introduction of air into said air chamber, and means to selectively vary the volume of air within said air chamber.

22. The combination as defined in claim 20, in which said means to selectively vary the volume of air within said hollow body and said air chamber of said air clutch comprises a source of compressed air, a control valve disposed between said source of compresses air and said hollow body and said air chamber, first conduit means connecting said control valve with said source of compressed air, second conduit means connecting said hollow body with said control valve and third conduit means connecting said air chamber of said air clutch with said control valve, said control valve being operable in a first position to selectively connect said third conduit with said first conduit to establish communication between said source of compressed air and said air chamber of said air clutch and operable in a second position to establish communication between said source of compressed air and said hollow body.

23. The combination as defined in claim 22, in which said control valve comprises a rotatable valve member having a first passage adapted for communication between said first conduit and said third conduit in a first position of said valve member to apply said air clutch, a second passage in said valve member open to the atmosphere adapted for communication of said third conduit with the atmosphere in a second position of said valve member to release said air clutch, a third passage in said valve member adapted for communication between said first conduit and said second conduit in a third position of said valve member for introduction of air into said hollow body to cause it to rise, and a fourth passage in said valve member open to the atmosphere adapted for communication of said second conduit with the atmosphere in a fourth position of said valve member to release air from said hollow body to cause said hollow body to sink.

24. The combination as defined in claim 20, in which said hollow body is provided with apertures to permit the entry of water into said hollow body in a submerged position of said hollow body and said control means being effective to vary the water to air ratio within said hollow body to cause said hollow body to be raised along said shaft upon the introduction of air into saidhollow body and to be lowered along said shaft upon the introduction of water into said hollow body.

25. The combination as defined in claim 20, in which said hollow body comprises a tank having an annular air chamber, a central chamber separate from said air chamber disposed around said shaft, said central chamber containing a fine chopping device and a suction means adapted to suck said vegetation cut off by said cutting device into said fine chopping device and means to drive said chopping device at a speed greater than said cutting device.

26. An apparatus for cutting underwater vegetation, comprising:

a longitudinal support member carrying a drive shaft,

means at one end of said support member for driving said shaft,

cutting means at the other end of said support member and driven by said shaft,

a balancing and positioning device carried by and intermediate the ends of said support member, said device being submersible and variably buoyant to vary the underwater positioning of said cutting means.

27. The apparatus as defined in claim 26 and in which said balancing and positioning device includes a vegetation collector and is variably longitudinally adjustable on said support member to vary its distance from said cutting means.

28. The apparatus as defined in claim 27 and including means selectively locking said collector at variable positions on said support member.

29. The apparatus as defined in claim 26 and including chopping means carried intermediate the ends of said support member to receive andfurther chop up vegetation cut by said cutting means.

30. The apparatus as defined in claim 27 and in which said collector includes chopping means operable to further chop up vegetation cut by said cutting means.

31. The apparatus as defined in claim 27 and in which said collector has means sucking thereinto vegetation cut by said cutting means.

32. The apparatus as defined in claim 31 and in which said collector contains therein means for chopping up vegetation sucked thereinto. 

1. Apparatus for cutting underwater vegetation comprising: a conveyance movable on the surface of a body of water, a vegetation collector carried by said conveyance, electrical power means and an air compressor carried by said conveyance, a longitudinal support member extending from said conveyance into said body of water and longitudinally movable relative thereto so as not to be affected by up and down movement of said conveyance, a cutting device rotatably attached to the lower end of said support member, and a submersible float means carried by said support member adapted to floatingly carry said support member and said cutting device in a submerged position within said body of water, said float means comprising an air chamber conneCted with said air compressor, said float means having an electric cutter driving means operably connected with said electrical power means, and suction means associated with said float means to extract said vegetation cutoff by said cutting device for disposal into said collector.
 2. The apparatus as defined in claim 1, further comprising control means associated with said compressor to control the amount of air within said air chamber of said float means.
 3. The apparatus as defined in claim 2, in which said air chamber of said float means is perforated to allow the introduction of water thereinto and said control means is effective to vary the ratio of air to water in said air chamber for changing the depth of said float means within said body of water.
 4. The apparatus as defined in claim 1, further comprising means to selectively lock said float means on said longitudinal support member at a preselected height above said cutting device, and said cutting device being provided with means to slow the descent of said cutting device upon release of said lock means.
 5. The apparatus as defined in claim 4, in which said selective locking means is an air clutch connected with said compressor.
 6. The apparatus as defined in claim 1, in which said float means contains a chopping device having rotatable chopping blades coaxially disposed above said cutting device and means to drive said chopping device at a speed greater than the rotational speed of said cutting device.
 7. The apparatus as defined in claim 6, in which said suction means is adapted to suck said vegetation cutoff by said cutting device into said chopping device for fine chopping of said vegetation.
 8. The apparatus as defined in claim 6, in which said means to drive said chopping blades of said chopping device comprises an electric motor contained within said float means connected for operation to said electrical power means.
 9. The apparatus as defined in claim 8, in which said suction means comprises a pump contained in said float means to be driven by said electric motor simultaneously with said chopping device.
 10. The apparatus as defined in claim 9, in which said pump comprises an impeller driven by said electric motor and further comprising means to drive said impeller in a direction opposite from the rotational direction of said chopping blades of said chopping device.
 11. The apparatus as defined in claim 10, in which said drive means comprises a reversing gear mechanism embodied in said float means.
 12. The apparatus as defined in claim 1, in which said suction means comprises a pump carried by said conveyance having a suction pipe connected to said float means and an ejection pipe connected to the outlet of said pump for disposal of said cut off vegetation into said collector.
 13. The apparatus as defined in claim 1, in which said cutting device comprises a pair of superimposed cutting blades and drive means to rotate said pair of cutting blades in opposite directions.
 14. The apparatus as defined in claim 13, in which said drive means comprises a reversing gear mechanism drivingly connected to said pair of cutting blades.
 15. The apparatus as defined in claim 1, in which said float means is connected to said conveyance by an extensible cable to counteract rotation of said float means around said longitudinal support member during operation of said apparatus.
 16. The apparatus as defined in claim 6, in which said float means if provided with an annular shield extending outwardly and downwardly towards said cutting device to effectively increase the suction of said suction means to guide said cut off vegetation into said chopping device.
 17. An underwater weed cutting device comprising: a drive shaft, a cutting mechanism for cutting off vegetation and drivingly connected to said drive shaft for rotation thereby, a submersible, buoyant, balancing and positioning device supported around said drive shaft, chopping means carriEd by said balancing and positioning device, suction means connected with said chopping means for sucking said vegetation cut off by said cutting mechanism into said chopping means, power means to drive said cutting mechanism and said chopping means, said balancing and positioning device provided with means for varying the buoyancy thereof to selectively vary the submerged depth of said cutting mechanism, and means to selectively vary the distance between said balancing and positioning device and said cutting mechanism along said drive shaft.
 18. In the device as defined in claim 17, said suction means comprising a closed chamber disposed within said balancing and positioning device in communication with said chopping means, said chamber having an outlet in communication with a suction pipe, said suction pipe being in communication with the inlet of a pump positioned remote from said balancing and positioning device and ejection means connected to the outlet of said pump for disposal of said vegetation cut off by said mechanism.
 19. In the device as defined in claim 17, adjustable locking means provided around said drive shaft to selectively retain said balancing and positioning device at a predetermined height around said drive shaft relative to said cutting mechanism, and means associated with said cutting mechanism to slow the descent of said cutting mechanism upon release of said locking means.
 20. In combination with an underwater vegetation-cutting device attached to an elongated shaft, a buoyant float means supported on said shaft, said float means comprising: a hollow body adapted to be selectively filled with air to increase or decrease its buoyance, means to lock said float means onto said shaft at infinitely variable selected positions along at least a portion of the shaft to vary spacing from said cutting device, and control means to selectively vary the volume of air within said hollow body to raise or to lower said cutting device when said float means is locked on said shaft.
 21. The combination as defined in claim 20, in which said means to lock said float means onto said shaft comprises an air clutch having a housing disposed around said shaft, an annular air chamber within said housing defined by an annular diaphragm having spaced walls, friction members secured to the outside of said spaced walls for frictional locking contact against said housing and said shaft upon the introduction of air into said air chamber, and means to selectively vary the volume of air within said air chamber.
 22. The combination as defined in claim 20, in which said means to selectively vary the volume of air within said hollow body and said air chamber of said air clutch comprises a source of compressed air, a control valve disposed between said source of compresses air and said hollow body and said air chamber, first conduit means connecting said control valve with said source of compressed air, second conduit means connecting said hollow body with said control valve and third conduit means connecting said air chamber of said air clutch with said control valve, said control valve being operable in a first position to selectively connect said third conduit with said first conduit to establish communication between said source of compressed air and said air chamber of said air clutch and operable in a second position to establish communication between said source of compressed air and said hollow body.
 23. The combination as defined in claim 22, in which said control valve comprises a rotatable valve member having a first passage adapted for communication between said first conduit and said third conduit in a first position of said valve member to apply said air clutch, a second passage in said valve member open to the atmosphere adapted for communication of said third conduit with the atmosphere in a second position of said valve member to release said air clutch, a third passage in said valve member adapted for communication beTween said first conduit and said second conduit in a third position of said valve member for introduction of air into said hollow body to cause it to rise, and a fourth passage in said valve member open to the atmosphere adapted for communication of said second conduit with the atmosphere in a fourth position of said valve member to release air from said hollow body to cause said hollow body to sink.
 24. The combination as defined in claim 20, in which said hollow body is provided with apertures to permit the entry of water into said hollow body in a submerged position of said hollow body and said control means being effective to vary the water to air ratio within said hollow body to cause said hollow body to be raised along said shaft upon the introduction of air into said hollow body and to be lowered along said shaft upon the introduction of water into said hollow body.
 25. The combination as defined in claim 20, in which said hollow body comprises a tank having an annular air chamber, a central chamber separate from said air chamber disposed around said shaft, said central chamber containing a fine chopping device and a suction means adapted to suck said vegetation cut off by said cutting device into said fine chopping device and means to drive said chopping device at a speed greater than said cutting device.
 26. An apparatus for cutting underwater vegetation, comprising: a longitudinal support member carrying a drive shaft, means at one end of said support member for driving said shaft, cutting means at the other end of said support member and driven by said shaft, a balancing and positioning device carried by and intermediate the ends of said support member, said device being submersible and variably buoyant to vary the underwater positioning of said cutting means.
 27. The apparatus as defined in claim 26 and in which said balancing and positioning device includes a vegetation collector and is variably longitudinally adjustable on said support member to vary its distance from said cutting means.
 28. The apparatus as defined in claim 27 and including means selectively locking said collector at variable positions on said support member.
 29. The apparatus as defined in claim 26 and including chopping means carried intermediate the ends of said support member to receive and further chop up vegetation cut by said cutting means.
 30. The apparatus as defined in claim 27 and in which said collector includes chopping means operable to further chop up vegetation cut by said cutting means.
 31. The apparatus as defined in claim 27 and in which said collector has means sucking thereinto vegetation cut by said cutting means.
 32. The apparatus as defined in claim 31 and in which said collector contains therein means for chopping up vegetation sucked thereinto. 